A code processing device according to the related art scans code symbols, which are attached on articles, one by one, by an operator and conducts processing on the basis of information obtained from the scanned code symbols. According to the code processing device, the operator has to find out the code symbol of each article and then match the code symbol and a code reading face of the code processing device each time. For that reason, a workload of the operator is large, and the workload increases as the number of articles to be scanned increases.
On the other hand, an RFID processing device reads information of articles from radio frequency identification (RFID) tags, which are respectively attached to the articles, and conducts processing on the basis of the read information. This processing device, for example, has a counter in which a flat antenna is embedded and collectively reads information of multiple articles that are placed on the counter from RFID tags attached thereto.
However, if an article with an RFID tag that is not a processing target is placed near the counter, the non-target RFID tag may be read together with the RFID tags attached to the articles to be processed. To handle this issue, an RFID processing device of one type has a metal electromagnetic-shielding box, in which is the articles to be processed are contained, and RFID tags attached to the articles are scanned using an RFID reader/writer of the RFID processing device.
The metal electromagnetic-shielding box has a metal door that is attached to an opening of the box, and a gasket that is formed of a conductor is disposed at a circumference of the opening to prevent leakage of radio waves of the RFID reader/writer from a gap between the box and the metal door.
The gasket can deteriorate due to repeated opening and closing operations of the door, hit or rub by the case, and other causes. For that reason, the gasket that deteriorated with age must be replaced, which causes increase in maintenance cost.
On the other hand, a choke structure, which is widely used in microwave ovens and high frequency heating devices, is an electromagnetic-shielding structure that is less likely to deteriorate and thereby require a less maintenance cost. However, this choke structure is formed by bending a metal in a complex manner, and an expensive mold is necessary to produce the choke structure.
In addition, the frequency of radio waves that are used in an RFID reader/writer is smaller than the frequency of microwaves that are used in microwave ovens. For example, the frequency of the radio waves may be 920 MHz, and the frequency of the microwaves maybe 2.4 GHz. Thus, when a choke structure having the same structure as that of the microwave oven is applied to the electromagnetic-shielding box, the choke structure may have to be excessively large.